The present invention is related to the field of agricultural tools and appliances, particularly related to the field of agricultural machinery, mainly that known as hauling machinery, which, at the same time, is self-propelling while being used.
There are many grain bagging machines known to be used to form silos inside very long bags made up of plastic endless sleeves, such bagging machines consisting of structures that can be attached to traction vehicles, having a receiving hopper to collect the grain from the harvester, the hopper being connected to a tunnel leading to an outlet which mouth has been previously fitted into the above-mentioned sleeve, which is conveniently folded to spread out as the silo is filled, such sleeve having an initial knot that determines its bottom, and being cut and knotted at the opposite end once the silo is full.
Such bagging machines are fitted with running gear and are pulled forward by a tractor, leaving behind the silo deposited on the ground.
The problem with all of them is that it is difficult to graduate their pace, which may result in an inadequate grain compacting due to a fast forward movement of the machine, or in the full sleeve not receiving the amount of grain dropping in through the hopper, thus causing the bagging machine to get saturated due to its slow forward movement.
It can then be inferred that it is desirable to have a bagging machine that moves forward at a speed determined by the amount of load received, i.e., a speed that allows it to synchronize its forward movement according to the amount of material that is fed into the machine, thus producing a homogenous compacted silage volume.
Patent AR 010974 B1, which is herein fully incorporated by way of reference, refers to a self-propelled bagging machine (1) for storing grain in a sleeve (M). The bagging machine (1) receives the grain load through an upper hopper (5), breaking down its drop force by means of an inside slant partition wall (6) so that a component of such force is capable of compacting the grain inside the silo (S) while the other component is capable of driving the machine (1) into a gradual forward movement. The bagging machine (1) is mounted onto a chassis (2) with running gear (10) fitted with a dragging pole to allow towing when not in operation, and has a width reduction device (3) for easy transportation.
The possibility to reduce the width of the machine for easy transportation involves a pivot system (3) with a central vertical shaft that links the chassis structure (2) with the actuator assembly (4) of the bagging machine (1) in such a way that, being the useful width of the actuator assembly (4) considerably larger than the running gear gage (10) and its length shorter, when hooked to the traction vehicle that will tow it to another workplace or the parking place, a 90° turn occurs, leaving such actuator assembly (4) with its shorter size crosswise, without exceeding the allowed gage width and ensuring a road traffic risk-free circulation. See FIGS. 1 and 2.
The bagging machine (1) described in said patent AR 010974 B1 optimizes the grain bagging operation, with the additional advantage of requiring a single traction vehicle for transportation while in inactive mode, thanks to its autonomous operation.
However, the grain bagging machine described in said patent has a few drawbacks, namely:                when used to feed grain into a silo, it moves forward too fast; this movement must be invariably graduated by braking so that bagging complies with the minimum effective storage requirements; and        attaching the bag to the support demands more than one worker, considering that the plastic bag weighs about 110 to 130 kg, which makes it impossible for a single man to place it in its working position.        
It should particularly be noted that the braking device (14) used by the grain bagging machine (1) described in patent AR 010974 B1 mentioned above is dual, meaning that each running gear wheel (10) in the machine (1) has an independent brake adjustment mechanism, which usually causes the machine (1) to go off the expected track if calibration is inadequate or asymmetrical. Likewise, calibrating two independent brakes (14) so that they may allow for a smooth forward movement is neither an easy nor a quick task.
On the other hand, the ground on which the machine runs is usually uneven, and such unevenness may alter the force breakdown generated during the grain drop, which, in addition to a different breakdown of the force of gravity acting on the machine's center of gravity, worsen the problems derived from an inadequate calibration of the braking device.
Therefore, in order to avoid the above-mentioned inconveniences during grain bagging, it is advisable to have a self-propelled bagging machine for storing grain in a sleeve that combines all of the following features: the ability to move forward in a controlled and effective way during grain bagging on any terrain, avoiding side slides off the track previously set by the operator, and allowing a single worker to attach the silo bag in the right position to be filled.